New insights into the GINS complex explain the controversy between existing structural models

DOI: 10.1038/srep40188

Authors: Marta Carroni (Imperial College London) , Matteo De March (Elettra Sincrotrone Trieste) , Barbara Medagli (Elettra Sincrotrone Trieste) , Ivet Krastanova (Elettra Sincrotrone Trieste) , Ian A. Taylor (The Francis Crick Institute) , Heinz Amenitsch (Graz University of Technology) , Hiroyuchi Araki (National Institute of Genetics, Japan) , Francesca M. Pisani (Istituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche) , Ardan Patwardhan (Imperial College London) , Silvia Onesti (Imperial College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Scientific Reports , VOL 7

State: Published (Approved)
Published: January 2017
Diamond Proposal Number(s): 11476

Abstract: GINS is a key component of eukaryotic replicative forks and is composed of four subunits (Sld5, Psf1, Psf2, Psf3). To explain the discrepancy between structural data from crystallography and electron microscopy (EM), we show that GINS is a compact tetramer in solution as observed in crystal structures, but also forms a double-tetrameric population, detectable by EM. This may represent an intermediate step towards the assembly of two replicative helicase complexes at origins, moving in opposite directions within the replication bubble. Reconstruction of the double-tetrameric form, combined with small-angle X-ray scattering data, allows the localisation of the B domain of the Psf1 subunit in the free GINS complex, which was not visible in previous studies and is essential for the formation of a functional replication fork.

Journal Keywords: DNA replication; Electron microscopy; SAXS

Subject Areas: Biology and Bio-materials


Instruments: B21-High Throughput SAXS

Other Facilities: Elettra

Added On: 30/01/2017 16:20

Documents:
srep40188.pdf

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Scattering Small Angle X-ray Scattering (SAXS)